1KLR

NMR Structure of the ZFY-6T[Y10F] Zinc Finger

Summary for 1KLR

• Entry DOI: 10.2210/pdb1klr/pdb
• Related: 1KLS 5ZNF
• Descriptor: ZINC FINGER Y-CHROMOSOMAL PROTEIN, ZINC ION (2 entities in total)
• Functional Keywords: zinc finger, transcription
• Cellular location: Nucleus: P08048
• Total number of polymer chains: 1
• Total formula weight: 3664.49

Authors

Lachenmann, M.J.,Ladbury, J.E.,Phillips, N.B.,Narayana, N.,Qian, X.,Weiss, M.A. (deposition date: 2001-12-12, release date: 2002-03-13, Last modification date: 2024-05-22)

Primary citation

Lachenmann, M.J.,Ladbury, J.E.,Phillips, N.B.,Narayana, N.,Qian, X.,Weiss, M.A.
The hidden thermodynamics of a zinc finger.
J.Mol.Biol., 316:969-989, 2002

PubMed Abstract: The Zn finger provides a model for studies of protein structure and stability. Its core contains a conserved phenylalanine residue adjoining three architectural elements: a beta-hairpin, an alpha-helix and a tetrahedral Zn(2+)-binding site. Here, we demonstrate that the consensus Phe is not required for high-affinity Zn(2+) binding but contributes to the specification of a precise DNA-binding surface. Substitution of Phe by leucine in a ZFY peptide permits Zn(2+)-dependent folding. Although a native-like structure is retained, structural fluctuations lead to attenuation of selected nuclear Overhauser enhancements and accelerated amide proton exchange. Surprisingly, wild-type Zn affinity is maintained by entropy-enthalpy compensation (EEC): a hidden entropy penalty (TDeltaDeltaS 7kcal/mol) is balanced by enhanced enthalpy of association (DeltaDeltaH -7kcal/mol) at 25 degrees C. Because the variant is less well ordered than the Phe-anchored domain, the net change in entropy is opposite to the apparent change in configurational entropy. By analogy to the thermodynamics of organometallic complexation, we propose that EEC arises from differences in solvent reorganization. Exclusion of Leu among biological sequences suggests an evolutionary constraint on the dynamics of a Zn finger.

PubMed: 11884136
DOI: 10.1006/jmbi.2001.5335

Experimental method

SOLUTION NMR